X++ to run XIRR

I created a small X++ wrapper to call XIRR function from the C# project provided by https://github.com/klearlending/XIRR (Thank you!) 

You can test XIRR function in Excel, btw.

using tmxExcelFinance;
/// <summary>
/// Implements various financial functions
/// </summary>
public final class myFinanceFunction
{
    /// <summary>
    /// Calculates XIRR value
    /// </summary>
    /// <param name = "_cashFlows">List of containers kind [cashflow amount, its date]</param>
    /// <param name = "_decimals">how many decimals to calculate</param>
    /// <param name = "_maxRate">Maximum rate</param>
    /// <returns>XIRR value</returns>
    public static real calculateXIRR(List _cashFlows, int _decimals, real _maxRate = 1000000)
    { 
         
        var                                 cashFlows       = new System.Collections.Generic.List<CashFlowDates>();
        System.Collections.IEnumerable      cashFlowsI;
        ListEnumerator                      leC             = _cashFlows.getEnumerator();
        System.Double                       dbl;
        System.DateTime                     dt;

        while(leC.moveNext())
        {
            [dbl, dt] = leC.current();
            cashFlows.Add(new CashFlowDates(dbl, dt));
        }
        // convert to iterable
        cashFlowsI = cashFlows;

        return XIRR::Calc(cashFlowsI, _decimals, _maxRate);
    }

}

This is how we can call the wrapper

 public static void calculateXIRRFromInvestmentDetailsLineTmp(RefRecId _projTableRecId, myInvestmentDetailsLineTmp _myInvestmentDetailsLineTmp)
    {
        List listCashFlowsDates = new List(Types::Container);

        myInvestmentDetailsLineTmp myInvestmentDetailsLineTmpLocal;

        myInvestmentDetailsLineTmpLocal.linkPhysicalTableInstance(_myInvestmentDetailsLineTmp);

        while select myInvestmentDetailsLineTmpLocal
        {
            listCashFlowsDates.addEnd([myInvestmentDetailsLineTmpLocal.TransactionCurrencyAmount, DateTimeUtil::newDateTime(myInvestmentDetailsLineTmpLocal.LineDate, 0)]);
        }
        myProjXIRRTable.XIRRValue = myFinanceFunction::calculateXIRR(listCashFlowsDates, 4);
...

Or

 cashFlows1 = new List (Types::Container);
        
        cashFlows1.addEnd([-10000,str2Date("01/01/2008", 123)]);
        cashFlows1.addEnd([2750, str2Date("01/03/2008", 123)]);
        cashFlows1.addEnd([4250, str2Date("30/10/2008", 123)]);
        cashFlows1.addEnd([3250, str2Date("15/02/2009", 123)]);
        cashFlows1.addEnd([2750, str2Date("01/04/2009", 123)]);

res = myFinanceFunction::calculateXIRR(cashFlows1, 10);

Notes about the solution creation.

D365FO project must be <TargetFrameworkVersion>v4.6</TargetFrameworkVersion>

Last remark. I tried to implemented the same algorithm in X++, but I bumped into two limitations.

First, there is a limit for recursion depth - 400 levels; we can flatten it, though. 

Second, real loses required decimals and ends up with division by zero.

TF command line to fix the error: Mapping on the working folder is already in use

 Just to document my command line to get rid of this blocking error.

My environment is under Azure DevOps version control and some other user already created a workspace on this computer.

Close Visual Studio (2017 in my case) and open the command line. It can be open via Developer Command Prompt for VS 2017; so you would not need to provide the entire path to tf.exe.

Next, run a tf command to delete the workspace created by the previous user (Name and Surname)

tf workspace /delete DEV365-FO-VM-3;"Name Surname" /collection:https://YOURCOMPANYPROJECT.visualstudio.com

Then stop all locally running D365FO services, like Web Publishing, Batch processing, etc, in order to avoid errors with locked files in your K:\AosService\PackagesLocalDirectory subfolders.

Now you can open Visual Studio, connect to Azure DevOps server, create a new workspace, map your folders for projects and metadata, and get latest.